Coordinate Converter – GPS & GIS Coordinate Transformer

Instantly convert coordinates across 31+ geodetic systems. Batch processing with full client-side privacy.

WGS84

Coordinate Picker Tools

Get coordinates from popular mapping services like Google Maps, AMap, Baidu Maps, and Tencent Maps to use in our converter.

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AMap Coordinate Picker

lbs.amap.com/tools/picker
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Baidu Coordinate Picker

api.map.baidu.com/lbsapi/getpoint
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Tencent Coordinate Picker

lbs.qq.com/getPoint
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Google Maps Coordinate Picker

google.com/maps

Supported Conversions

Convert coordinates between 31+ geodetic systems with professional-grade accuracy

North American Systems
NAD27
NAD83
Global Systems
WGS84
UTM
MGRS
Chinese Systems
GCJ-02
BD-09
CGCS2000
BJ54
BJ2000
Xian80
European Systems
OSGB36
ETRS89
ED50
HTRS96
EOV
CH1903+
RGF93
Lambert-93
Asian Systems
JGD2011
JGD2000
PRS92
GDM2000
Indian 1975
KGD2002
Historical Systems
Clarke 1880
South American Systems
SIRGAS2000
Australian Systems
GDA2020
GDA94
NZGD2000
Format Conversions
DMS
DDM
Decimal
BNG

Batch conversion with unlimited entries

Export results as XLSX files

100% client-side processing - your data stays private

34+ coordinate format support

⚙️ 7-Parameter Helmert Transformation

The 7-parameter Helmert transformation (also known as time-tested similarity transformation) is a mathematical method used to convert coordinates between two different geodetic datums. It shifts, rotates, and scales the coordinate system in 3D space to align one datum with another. This is essential when converting between local historical datums (like BJ54, ED50, Xian80) and the global WGS84 system.

Different countries and regions developed their own geodetic datums using different ellipsoids and reference points. For example, China uses BJ54 (Krasovsky 1940 ellipsoid), Xian80 (IAG75 ellipsoid), and CGCS2000 (GRS80 ellipsoid). To convert coordinates between these systems and WGS84, we use 7-parameter Helmert transformation because the datums differ in origin (3 shifts), orientation (3 rotations), and scale (1 factor).

Translation Parameters

dx, dy, dz (meters) - shifts along X, Y, Z axes of the Earth-centered reference frame

Rotation Parameters

rx, ry, rz (radians) - rotations around each axis to align datum orientations

Scale Parameter

s (ppm) - scale factor adjusting for size differences between ellipsoids

# Common 7-parameter example: ED50 → WGS84 (European area)
dx=-87  dy=-96  dz=-120  rx=0   ry=0   rz=0   s=0

# BJ54 → WGS84 (China area, regional parameters may vary)
dx=31.4  dy=144.3  dz=74.8  rx=0  ry=0  rz=0  s=0

# Note: Accurate parameters depend on your specific region.
# Consult local surveying authorities for official values.
Systems requiring 7-parameter transformation: BJ54, BJ2000, Xian80, ED50, HTRS96, GDM2000, PRS92, Clarke1880, Indian1975. Enter the parameters provided by your local surveying authority for accurate results.
📐 DMS, DDM, Decimal & BNG Coordinate Formats & Lambert-93
DMS (Degrees, Minutes, Seconds)

A sexagesimal notation where coordinates are expressed in degrees (°), minutes ('), and seconds ("). The traditional format used in paper maps and GPS devices.

Example: 23°3'3.78"N, 113°22'17.36"E

Degree (°), Minute ('), Second ("), Hemisphere (N/S/E/W)
DDM (Degrees & Decimal Minutes)

A coordinate format where degrees are followed by minutes expressed as a decimal fraction. Widely used in GPS receivers, NMEA sentences, USGS topo maps, and aviation charts. DDM combines human-readable degrees with precise decimal minutes.

Example: 40°26.7717'N, 79°58.9336'W

Degree (°), Decimal Minutes ('), Hemisphere (N/S/E/W)
Decimal (Decimal Degrees)

Degrees expressed as a single decimal fraction. The most widely used format in digital mapping and GIS software.

Example: 23.05105, 113.37149

Latitude, Longitude
BNG (British National Grid)

A metric grid system used by the Ordnance Survey for all official UK mapping. Coordinates are expressed as easting and northing in meters, projected from OSGB36 using a Transverse Mercator projection.

Example: 530000 180000 (London area)

Easting (m), Northing (m)
Lambert-93 (French Projection)

Official French Lambert Conformal Conic projection used by IGN for all national mapping. Coordinates are expressed in meters.

Example: 652000 6850000 (Paris area)

Easting (m), Northing (m)